In the manufacture of envelopes, blanks can be cut from paper stock and formed into a pile. Thereafter, successive ones of the blanks from the pile are fed into an envelope-making machine where they are gummed and folded into completed envelopes. In copending application Ser. No. 547,988, filed Feb. 7, 1975 and assigned to the Assignee of the present application, rotary die cutting apparatus is described wherein multiple dies on a rotary cutting drum are provided with each pair of adjoining dies having a common side forming a single cut between them. In this manner, scrap is reduced to a minimum since, in the cutting operation, the side flap of one envelope is in-line with the side flap of an adjacent envelope along the direction of movement of the web from which the blanks are cut.
One disadvantage of the apparatus shown in the aforesaid copending application, however, is that the sealing flap of one adjacent envelope blank faces in a direction opposite that of the adjacent blank. As a result, the die cutting apparatus shown in the aforesaid copending application requires that one-half of the blanks be reversed and that all blanks be formed into a pile before they are fed into an envelope-making machine.
Instead of feeding blanks one-by-one into an envelope-making machine from a stack of such blanks, it is also possible to cut the blanks from a continuously moving web. After being cut from the web, the blanks are fed, without stopping and without having to be formed into a stack, into the gumming and folding portions of the envelope-making machine. This, however, requires that all of the sealing flaps of the envelopes point in the same direction along the direction of movement of the web, meaning that the apparatus shown in the aforesaid copending application is unsatisfactory for this purpose.